From: Andiry Xu <jix...@cs.ucsd.edu>

Upon system failure, NOVA needs to scan all the inode logs
to rebuild the allocator. During the scanning, NOVA stores allocated
log/data pages in a bitmap, and uses the bitmap to rebuild the allocator
once scan finishes.

Signed-off-by: Andiry Xu <jix...@cs.ucsd.edu>
---
 fs/nova/bbuild.c | 252 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/nova/bbuild.h |  18 ++++
 2 files changed, 270 insertions(+)

diff --git a/fs/nova/bbuild.c b/fs/nova/bbuild.c
index ca51dca..35c661a 100644
--- a/fs/nova/bbuild.c
+++ b/fs/nova/bbuild.c
@@ -414,6 +414,258 @@ void nova_save_blocknode_mappings_to_log(struct 
super_block *sb)
                  pi->log_head, pi->log_tail);
 }
 
+/************************** Bitmap operations ****************************/
+
+static inline void set_scan_bm(unsigned long bit,
+       struct single_scan_bm *scan_bm)
+{
+       set_bit(bit, scan_bm->bitmap);
+}
+
+inline void set_bm(unsigned long bit, struct scan_bitmap *bm,
+       enum bm_type type)
+{
+       switch (type) {
+       case BM_4K:
+               set_scan_bm(bit, &bm->scan_bm_4K);
+               break;
+       case BM_2M:
+               set_scan_bm(bit, &bm->scan_bm_2M);
+               break;
+       case BM_1G:
+               set_scan_bm(bit, &bm->scan_bm_1G);
+               break;
+       default:
+               break;
+       }
+}
+
+static int nova_insert_blocknode_map(struct super_block *sb,
+       int cpuid, unsigned long low, unsigned long high)
+{
+       struct nova_sb_info *sbi = NOVA_SB(sb);
+       struct free_list *free_list;
+       struct rb_root *tree;
+       struct nova_range_node *blknode = NULL;
+       unsigned long num_blocks = 0;
+       int ret;
+
+       num_blocks = high - low + 1;
+       nova_dbgv("%s: cpu %d, low %lu, high %lu, num %lu\n",
+               __func__, cpuid, low, high, num_blocks);
+       free_list = nova_get_free_list(sb, cpuid);
+       tree = &(free_list->block_free_tree);
+
+       blknode = nova_alloc_blocknode(sb);
+       if (blknode == NULL)
+               return -ENOMEM;
+       blknode->range_low = low;
+       blknode->range_high = high;
+       ret = nova_insert_blocktree(sbi, tree, blknode);
+       if (ret) {
+               nova_err(sb, "%s failed\n", __func__);
+               nova_free_blocknode(sb, blknode);
+               goto out;
+       }
+       if (!free_list->first_node)
+               free_list->first_node = blknode;
+       free_list->last_node = blknode;
+       free_list->num_blocknode++;
+       free_list->num_free_blocks += num_blocks;
+out:
+       return ret;
+}
+
+static int __nova_build_blocknode_map(struct super_block *sb,
+       unsigned long *bitmap, unsigned long bsize, unsigned long scale)
+{
+       struct nova_sb_info *sbi = NOVA_SB(sb);
+       struct free_list *free_list;
+       unsigned long next = 0;
+       unsigned long low = 0;
+       unsigned long start, end;
+       int cpuid = 0;
+
+       free_list = nova_get_free_list(sb, cpuid);
+       start = free_list->block_start;
+       end = free_list->block_end + 1;
+       while (1) {
+               next = find_next_zero_bit(bitmap, end, start);
+               if (next == bsize)
+                       break;
+               if (next == end) {
+                       if (cpuid == sbi->cpus - 1)
+                               break;
+
+                       cpuid++;
+                       free_list = nova_get_free_list(sb, cpuid);
+                       start = free_list->block_start;
+                       end = free_list->block_end + 1;
+                       continue;
+               }
+
+               low = next;
+               next = find_next_bit(bitmap, end, next);
+               if (nova_insert_blocknode_map(sb, cpuid,
+                               low << scale, (next << scale) - 1)) {
+                       nova_dbg("Error: could not insert %lu - %lu\n",
+                               low << scale, ((next << scale) - 1));
+               }
+               start = next;
+               if (next == bsize)
+                       break;
+               if (next == end) {
+                       if (cpuid == sbi->cpus - 1)
+                               break;
+
+                       cpuid++;
+                       free_list = nova_get_free_list(sb, cpuid);
+                       start = free_list->block_start;
+                       end = free_list->block_end + 1;
+               }
+       }
+       return 0;
+}
+
+static void nova_update_4K_map(struct super_block *sb,
+       struct scan_bitmap *bm, unsigned long *bitmap,
+       unsigned long bsize, unsigned long scale)
+{
+       unsigned long next = 0;
+       unsigned long low = 0;
+       int i;
+
+       while (1) {
+               next = find_next_bit(bitmap, bsize, next);
+               if (next == bsize)
+                       break;
+               low = next;
+               next = find_next_zero_bit(bitmap, bsize, next);
+               for (i = (low << scale); i < (next << scale); i++)
+                       set_bm(i, bm, BM_4K);
+               if (next == bsize)
+                       break;
+       }
+}
+
+struct scan_bitmap *global_bm[MAX_CPUS];
+
+static int nova_build_blocknode_map(struct super_block *sb,
+       unsigned long initsize)
+{
+       struct nova_sb_info *sbi = NOVA_SB(sb);
+       struct scan_bitmap *bm;
+       struct scan_bitmap *final_bm;
+       unsigned long *src, *dst;
+       int i, j;
+       int num;
+       int ret;
+
+       final_bm = kzalloc(sizeof(struct scan_bitmap), GFP_KERNEL);
+       if (!final_bm)
+               return -ENOMEM;
+
+       final_bm->scan_bm_4K.bitmap_size =
+                               (initsize >> (PAGE_SHIFT + 0x3));
+
+       /* Alloc memory to hold the block alloc bitmap */
+       final_bm->scan_bm_4K.bitmap = kzalloc(final_bm->scan_bm_4K.bitmap_size,
+                                                       GFP_KERNEL);
+
+       if (!final_bm->scan_bm_4K.bitmap) {
+               kfree(final_bm);
+               return -ENOMEM;
+       }
+
+       /*
+        * We are using free lists. Set 2M and 1G blocks in 4K map,
+        * and use 4K map to rebuild block map.
+        */
+       for (i = 0; i < sbi->cpus; i++) {
+               bm = global_bm[i];
+               nova_update_4K_map(sb, bm, bm->scan_bm_2M.bitmap,
+                       bm->scan_bm_2M.bitmap_size * 8, PAGE_SHIFT_2M - 12);
+               nova_update_4K_map(sb, bm, bm->scan_bm_1G.bitmap,
+                       bm->scan_bm_1G.bitmap_size * 8, PAGE_SHIFT_1G - 12);
+       }
+
+       /* Merge per-CPU bms to the final single bm */
+       num = final_bm->scan_bm_4K.bitmap_size / sizeof(unsigned long);
+       if (final_bm->scan_bm_4K.bitmap_size % sizeof(unsigned long))
+               num++;
+
+       for (i = 0; i < sbi->cpus; i++) {
+               bm = global_bm[i];
+               src = (unsigned long *)bm->scan_bm_4K.bitmap;
+               dst = (unsigned long *)final_bm->scan_bm_4K.bitmap;
+
+               for (j = 0; j < num; j++)
+                       dst[j] |= src[j];
+       }
+
+       ret = __nova_build_blocknode_map(sb, final_bm->scan_bm_4K.bitmap,
+                       final_bm->scan_bm_4K.bitmap_size * 8, PAGE_SHIFT - 12);
+
+       kfree(final_bm->scan_bm_4K.bitmap);
+       kfree(final_bm);
+
+       return ret;
+}
+
+static void free_bm(struct super_block *sb)
+{
+       struct nova_sb_info *sbi = NOVA_SB(sb);
+       struct scan_bitmap *bm;
+       int i;
+
+       for (i = 0; i < sbi->cpus; i++) {
+               bm = global_bm[i];
+               if (bm) {
+                       kfree(bm->scan_bm_4K.bitmap);
+                       kfree(bm->scan_bm_2M.bitmap);
+                       kfree(bm->scan_bm_1G.bitmap);
+                       kfree(bm);
+               }
+       }
+}
+
+static int alloc_bm(struct super_block *sb, unsigned long initsize)
+{
+       struct nova_sb_info *sbi = NOVA_SB(sb);
+       struct scan_bitmap *bm;
+       int i;
+
+       for (i = 0; i < sbi->cpus; i++) {
+               bm = kzalloc(sizeof(struct scan_bitmap), GFP_KERNEL);
+               if (!bm)
+                       return -ENOMEM;
+
+               global_bm[i] = bm;
+
+               bm->scan_bm_4K.bitmap_size =
+                               (initsize >> (PAGE_SHIFT + 0x3));
+               bm->scan_bm_2M.bitmap_size =
+                               (initsize >> (PAGE_SHIFT_2M + 0x3));
+               bm->scan_bm_1G.bitmap_size =
+                               (initsize >> (PAGE_SHIFT_1G + 0x3));
+
+               /* Alloc memory to hold the block alloc bitmap */
+               bm->scan_bm_4K.bitmap = kzalloc(bm->scan_bm_4K.bitmap_size,
+                                                       GFP_KERNEL);
+               bm->scan_bm_2M.bitmap = kzalloc(bm->scan_bm_2M.bitmap_size,
+                                                       GFP_KERNEL);
+               bm->scan_bm_1G.bitmap = kzalloc(bm->scan_bm_1G.bitmap_size,
+                                                       GFP_KERNEL);
+
+               if (!bm->scan_bm_4K.bitmap || !bm->scan_bm_2M.bitmap ||
+                               !bm->scan_bm_1G.bitmap)
+                       return -ENOMEM;
+       }
+
+       return 0;
+}
+
+
 /*********************** Recovery entrance *************************/
 
 /* Return TRUE if we can do a normal unmount recovery */
diff --git a/fs/nova/bbuild.h b/fs/nova/bbuild.h
index 2c3deb0..b093e05 100644
--- a/fs/nova/bbuild.h
+++ b/fs/nova/bbuild.h
@@ -1,6 +1,24 @@
 #ifndef __BBUILD_H
 #define __BBUILD_H
 
+enum bm_type {
+       BM_4K = 0,
+       BM_2M,
+       BM_1G,
+};
+
+struct single_scan_bm {
+       unsigned long bitmap_size;
+       unsigned long *bitmap;
+};
+
+struct scan_bitmap {
+       struct single_scan_bm scan_bm_4K;
+       struct single_scan_bm scan_bm_2M;
+       struct single_scan_bm scan_bm_1G;
+};
+
+
 void nova_init_header(struct super_block *sb,
        struct nova_inode_info_header *sih, u16 i_mode);
 void nova_save_inode_list_to_log(struct super_block *sb);
-- 
2.7.4

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

Reply via email to